SU1375567A1 - Method of treating effluents of sulfate pulp production - Google Patents

Abstract

The invention relates to wastewater treatment methods, can be used in flotation treatment of wastewater containing sludge-lignin, in the pulp and paper industry, for flotation extraction of valuable components from slurries in the mining and chemical industry and allows for improved cleaning, increase flotation rate and reduce sediment moisture. Purification is carried out by administration. in the treated waters containing coagulant - aluminum sulphate, flocculant nta.type polyacrylamide; and flotation reagent-copolymer of vinyl ether of monoethanolamine with vinyl ester of N-cyanoethylethanolamine of general formula 4CHrCHV cHfCHV OCH2CH2N22H2CH2H2CH2H2CH2CH2CH2CH2V2H2CH2CH2V2H2CH2H2CH2V2H2CH2V2H2CH2V2H2CH2V2H2CH2V2H2CH2V2H2CH2V2H2CH2V2H2CH2V2CH2V2CH2V2CH2V2CH2V2CH2V2CH2V2CH2CH2V2CH2CH2V2CH2CH2V2CH2 where, with subsequent separation of the sediment flotation. Flotation reagent is prepared by cyanoethylation of monoethanolamine polyvinyl ether with acrylonitrile. The composition of the copolymer is determined by the ratio of the starting components. When treating wastewater containing 4.3 g / l of sludge-lignin and 18-20 mg / l of Alj (S04) j (Al), by injecting flocculant in the amount of 1 g / kg of dry sludge-minin (S. .-p.) and flotation reagent in the amount of 8-24 g / kg N.L. the degree of purification from suspended substances is 93-95%, the efficiency of reducing color is 98%, the flotation rate is 6-8 ml / s. 2 tabl; from C 00 "h SP ate 9d 1

Description

The invention relates to wastewater treatment methods and can be used in the flotation treatment of wastewater containing sludge lignin in pulp and paper npoMbmraeHHODTH, as well as in the flotation extraction of valuable components from slurries and production solutions in the mining and chemical and chemical industries. .

The purpose of the invention is to increase the degree of purification, increase the rate of flotation and decrease the moisture content of the sediment.

The method is carried out by introducing NIN into the treated waters containing coagulant aluminum sulphate, flocculant, and flotation reagent — a copolymer of vinyl ether of monoethanolamine with vinyl ether of N-cyanoethylethanolamine of the general formula

4CHrCHV- CH2-CHVm

 OCH2CH2l HCH2CH CN

 where, with the subsequent separation of sediment flotation,

Flotation reagent is obtained by cyanoethylation of monoethanolamine polyvinyl ether with acrylonitrile

(mCH2 CH-CN-4CH2-CH} pj- (V

OCH CH ISIH OCH2CH2NH2 OCH2CH2NHCH2CH2CN

The reaction proceeds spontaneously with a simple displacement of the starting components. The composition of the copolymer obtained is completely determined by the ratio of the initial reagents, so that it can be easily and continuously adjusted.

The copolymer is a light brown, viscous oil, soluble in water.

Example 1. Synthesis of monoethanolamine vinyl ether copolymer with N-cyanoethylethanolamine vinyl ether with a monomer ratio of 1: 1 (n: m 1: 1) ..

To 87.13 g of polyvinyl ether monoethanolamine (degree of polymerization, mol.m. 620), with stirring, add 26.53 g (0.5 mol of acrylonitrile at such a rate that the temperature of the reaction mixture does not exceed 3 sec. After adding the whole acrylonitrile mixture The mixture is kept for 6 hours at room temperature, 113.66 g (100%) of the copolymer are obtained in the form of a light brown viscous oil, soluble in water, mol.m., Mer 803.

Found,%: C 58.62) 58.77; H 9.32; 9.58, N 19.06, 19.12.

Vyisleno,%: C 58.12, H 9.31) N 18.49.

The IR spectrum of the substance contains bands: 2250 cm (), 3350-3450 cmH (W, W).

As wastewater, the wastewater of the Baikal Pulp and Paper Mill, containing

psham lignin in the amount of 4.3 g / l and coagulant - aluminum sulfate 18-20 mg / l (AI).

Example2. To a sample of 500 ml of wastewater, 1-4 ml of a 0.5% aqueous solution of a flotation reagent — a copolymer of vinyl ether of monoethanolamine with vinyl ether of N-cyanoethylethanolamine is added. The sample is saturated with air at a pressure of 0.2 MPa and fed to the flotation column simultaneously with flocculant. As flocculant, Santfloc is used, which is similar in properties to polyacrylamide.

The kinetics of the flotation process is evaluated by the volume of compacted sludge lignin. Sc: flotation orbity 6-8 ml / s, the degree of purification from suspended substances 93-95%, the effectiveness of reducing the color of 98%.

Table 1 presents data on the efficiency of the flotation process, depending on the dose of the flotation reagent at a pressure of 2.5 MPa and a dose of flocculant 1 g / kg of dry slime lignin (g / kg C.L.).

Table 2 presents comparative data on the efficiency of the purification process in a known manner and proposed using copolymer of monoethanolamine vinyl ether with N-cyanoethyl ethanolamine vinyl ether as a flotation reagent.

Claims (1)

Invention Formula A wastewater sulphate cellulose production purification method, a copolymer of monoethanolamine vinyl ether and N-cyanoethylethanolamine vinyl ether is introduced into the reactant agent. The introduction of coagulant, flocculant and flotation reagent followed by separation of sediment by flotation, which is characterized by the fact that, with the aim of formula 5 increase the degree of purification, increase h 1 i neither the flotation rate and the decrease in OCH2CH 2iNH2 OCH.CH jNHCH jCH CN moisture precipitate, as a floto where. Table 1 Flotation constant, 10 -C. Concentration of sludge-lignin in wastewater, g / l Dose of coagulant in the optimal reagent is introduced monoethanolamine vinyl ether copolymer with N-cyanoethylethanolamine vinyl ether, 0.20 1.20 1.35 1.82 2.0 4.3-6.0.